For those with Magnums - What Mounts did you use?

To answer - this is a 1971 Duster /6 Currently. I am replacing the /6 K frame with a spool mount V8 K.
I'm putting in a 360 Magnum (I was told the 318 and 360 mag's had the same mounts, maybe that's incorrect? )
Attaching a photo of the engine for reference.

What I believe I have figured out is that I have 318 LA Mounts which is why I have a gap.
So my options are to use a spacer, washers, or pick up a 340/360 mount.

Either way cheap and easy fix, and I will most likely fabricate a spacer.

Thanks all for the assist!

View attachment 1715321358
Hey man! Lookin slick!